This study will provide new information on the efficacy of capnography for early detection of hypoxemia during nurse-administered propofol sedation in adults. Previous studies, involving a paediatric randomized study and a study in adult gastrointestinal endoscopy, were outcome studies with capnography in patients sedated with midazolam in combination with fentanyl or meperidine.4 5 Therefore, we will assess the efficacy of interventions based on capnographic monitoring of respiratory function in nurse-administered propofol sedation. In previously conducted studies independent observers monitored the capnographic display and prompted the medical team of the changes in respiratory activity. In the following clinical trial we will examine normal practice by assessment of the capnogram by the nurse qualified in sedation management.